Next generation of selenocyanate and diselenides with upgraded leishmanicidal activity

•A new library of 20 selenocyanate and diselenide derivatives were synthesized.•Compounds B8 and B9 show EC50 of 7.7 µM and 5.7 µM in L. major amastigotes.•Diselenides B8 and B9 present EC50 of 6.0 µM and 7.4 µM in L. infantum amastigotes.•B8 and B9 exert high selectivity (60 < SI > 70) in bone marrow-derived macrophages.•TryR inhibition activity of B8 and B9 (IC50 7.6 and 9.2 µM) is higher than mepacrine.